package algorithm;

public class T00013 {

    public static void main(String[] args) {
        System.out.println(new Solution().romanToInt("MCMXCIV"));
    }

static class Solution {
    public int romanToInt(String s) {
        int num = 0; // 总
        int right = 0; // 右值
        for (int index = s.length() - 1; index >= 0; index --) {
            int t = getValue(s.charAt(index));
            if(t < right) { // 如果左边的值比右边小
                num -= t;
            } else {
                num += t;
                right = t;
            }
        }
        return num;
    }

    private int getValue(char c) {
        switch (c) {
            case 'I': return 1;
            case 'V': return 5;
            case 'X': return 10;
            case 'L': return 50;
            case 'C': return 100;
            case 'D': return 500;
            case 'M': return 1000;
            default: return 0;
        }
    }
}
}
